Add database pod and service for ruby sample app demo

- [x] update ruby-sample-app image with MySQL connection for Sinatra app 
- [x] change docker image URL with OpenShift official image for ruby-sample-app - https://github.com/openshift/ruby-hello-world/pull/5
that's what i meant by the "value generator", the value generator is what you use if you just want to explicitly set the value.  It takes on parameter, the value you want to use.